[PATCH] D62686: [RISCV] Add support for save/restore of callee-saved registers via libcalls

[Lewis Revill via Phabricator via llvm-commits]

lewis-revill marked an inline comment as done.
lewis-revill added inline comments.


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Comment at: llvm/lib/Target/RISCV/RISCVFrameLowering.cpp:289
   unsigned CFIIndex = MF.addFrameInst(
       MCCFIInstruction::createDefCfaOffset(nullptr, -StackSize));
   BuildMI(MBB, MBBI, DL, TII->get(TargetOpcode::CFI_INSTRUCTION))
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shiva0217 wrote:
> Should the -StackSize be -RealStackSize?
Looks like it, good catch.


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Comment at: llvm/lib/Target/RISCV/RISCVFrameLowering.cpp:668
+        .setMIFlag(MachineInstr::FrameSetup);
+
+    // Add registers spilled in libcall as liveins.
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shiva0217 wrote:
> GCC will generate stack adjustment and GPR callee saved CFIs for the save libcalls. Should we do the same?
I'm not familiar with the use of the CFI offset stuff, though just to be sure, you're saying that in addition to the manually-added `.cfi_offset`s in the libcalls themselves we would want to add them in our frame too?


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  https://reviews.llvm.org/D62686/new/

https://reviews.llvm.org/D62686